Method for including a self-removing indicator in a self-removing message

ABSTRACT

Methods, articles, signals, and systems are provided for providing email message originators and distributors with default control over message removal at a message recipient&#39;s location, regardless of whether the message has been opened. For instance, a self-removing message is designated as such by the message&#39;s originator, and a self-removal enhancement is added to conventional message content before the message is transmitted over a computer network toward one or more recipients. At the recipient&#39;s location, the message is automatically deleted without additional effort by the recipient, before or after being displayed, according to the originator&#39;s instructions unless they are overridden by the recipient. Messages may be automatically deleted in response to the arrival of a replacement message. Thus, the burden of removing unsolicited email messages is transferred from recipients to the system and the message&#39;s originators and/or to ISPs and other email distributors. Security of messages may also be enhanced.

RELATED APPLICATIONS

This application is a continuation-in-part of commonly owned copendingapplication Ser. No. 09/399,066 filed Sep. 18, 1999, now pending,through which this application also claims priority to application Ser.No. 60/101,517 filed Sep. 23, 1998 and to application Ser. No.60/104,138 filed Oct. 14, 1998.

FIELD OF THE INVENTION

The present invention relates to the technical goal of facilitating theuse of email (electronic mail) and similar broadcast or targetedtransmission mechanisms by automatically deleting information copiesafter their receipt.

TECHNICAL BACKGROUND OF THE INVENTION

Email is a very useful tool for promoting communication between peoplewho are separated by distance, by different working hours, or both.However, email is sometimes inconvenient for recipients. This hindersthe use of email as a mechanism for broad-casting information to manypeople and/or transmitting information to one or a few specific targets.

Email creates annoyances which have not been fully addressed. One commonsource of annoyance is “spam” email, namely, unsolicited email sent tomultiple recipients. Unlike passive advertising, such as pop-up andbanner ads on websites, and ads in more traditional print, radio, ortelevision media, “spam” email seeks out its audience, and thrustsitself into the viewer's field of attention without being invited. Thiscan be very annoying because it interrupts other activities, consumessystem resources, and perhaps most importantly, requires active effortsby recipients who want to dispose of these unwanted messages. An emailrecipient may delete unwanted messages manually by using an email Deletecommand in an email client (e.g., a desktop application program, or webmail pages in a web browser), by dragging the messages in question to atrash can, or by similar steps.

Some email systems provide filters that detect at least some incomingunsolicited email and either deletes it or, more typically, places it ina directory or folder reserved for such messages. But filters sometimeserr, either by characterizing as unsolicited email a message that isnot, or by failing to detect unsolicited email and letting it throughwith the normal correspondence from familiar senders. Thus, it would behelpful to provide some alternate or additional means for disposing ofunsolicited email.

Some unsolicited email includes a statement that sending a reply with“REMOVE” in the subject field will remove the recipient from the mailinglist. It has been alleged, however, that any reply to some suchunsolicited email will simply confirm that the address to which theunsolicited mail was sent is “good” (meaning someone actually looked atthe unsolicited email) and that a reply asking to be removed from themailing list may therefore have an effect opposite from the intendedeffect. If this is so, then only addresses from which no reply isreceived would have a chance of being removed from the list.

Moreover, even some mail which is unsolicited is of interest to therecipient only for a limited time. For instance, the fact that arecipient has voluntarily subscribed to an electronic newsletter, a newsservice, or a listserv list does not necessarily mean that the recipientwants to keep every message from that subscription after reading it.Indeed, despite having subscribed to the service, the recipient may noteven want to read each and every message from the subscription service.

Television and radio “spots” which broadcast an advertisement withouttaking up storage space on the receiver (televisions and radiosgenerally lack permanent storage such as hard disks) are known, althoughthis characterization of them as not requiring recipient storageresources and proactive deletion by the recipient may be new.

Accordingly, it would be an advancement to provide an improved approachto email and similar messaging which moves the email message disposalburden off the shoulders of the recipient. In particular and withoutlimitation, it would be an advance to make public notices and news sentthrough email less onerous to recipients, and likewise to make emailadvertisements (including without limitation coupons, contactinformation, descriptions of goods and/or services, comparisons, andpromotional materials) available to multiple recipients withoutrequiring that recipients affirmatively remove unwanted advertisementsfrom their computer systems or create a reply message having REMOVE oranother keyword in the subject, to indicate their lack of interest inthe subject matter being advertised.

Such approaches for improved email messaging are disclosed and claimedherein.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to methods, articles, signals, and systemsfor self-removing email messages. Self-removal of email (or othertransmitted digital information presentations) can provide at least twoadvantages. First, self-removing email can be used to enhance thesecurity of a system by reducing the number of message copies and thelife span of those copies. Second, self-removing email can be used toreduce the inconvenience of unsolicited email by making it possible forofficials, advertisers, and other broadcast email originators to presentmessages that do not have to be manually removed by the target audience.A given method, article, signal, or system may use self-removing emailto enhance message security, to reduce recipient annoyance, or both.

In some embodiments, self-removing email messages are encrypted withconventional tools and techniques. To further enhance security, amessage is closely coupled to executable code which reduces the numberof copies of the message. Some versions of the code allow any given copyof the message to be viewed at most once.

In some embodiments, self-removing email messages containadvertisements, but the invention may also be used to broadcast orotherwise transmit self-removing email messages which contain othermaterials that, at least by default, are not stored long-term on therecipient's hard disk or on other intervening nodes (the self-removalaction may sometimes be expressly overridden). For instance, news items,confidential materials, and other materials directed to a limitedaudience such as public notices (changes in the law, election results,tax auction notices, public hearing announcements, and so on), privateclub notices, and materials intended for mature audiences, may also betransmitted in self-removing email messages.

Unlike traditional email, self-removing email places the burden ofselecting messages for removal and then removing them on the softwareand on the message originator, instead of on the message recipient.“Spam” advertising methods become much less onerous to recipients if theemail carrying the advertisements is as effortlessly ephemeral (from therecipient's point of view) as a television or radio commercial. Otheraspects and advantages of the present invention will become more fullyapparent through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

To illustrate the manner in which the advantages and features of theinvention are obtained, a more particular description of the inventionwill be given with reference to the attached drawings. These drawingsonly illustrate selected aspects of the invention and thus do not limitthe invention's scope. In the drawings:

FIG. 1 is a diagram illustrating computers and computer networkssuitable for use according to the invention by means of configurationwith special-purpose hardware and/or software described herein.

FIG. 2 is a data flow diagram illustrating a method, signal, andenvironment using self-removing messages to carry messages from anoriginator through a network to one or more recipients.

FIG. 3 is a data flow diagram further illustrating embodiments of theinvention used to increase recipient convenience, and also furtherillustrating removal indicators and removal code shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In describing methods, devices, and systems according to the invention,the meaning of several important terms is clarified, so the claims mustbe read with careful attention to these clarifications. Specificexamples are given to illustrate aspects of the invention, but those ofskill in the relevant art(s) will understand that other examples mayalso fall within the meaning of the terms used, and hence within thescope of one or more claims. Important terms are defined, eitherexplicitly or implicitly, both here in the Detailed Description andelsewhere in the application file.

Computers, Networks

The invention may be used to protect and/or ultimately remove emailmessages from an individual computer or from one or more computers in anetwork, including copies of messages stored on removable media ortransmitted over a network link and stored on intermediate nodes. FIG. 1illustrates a system 100 having several computers and several networks102, 104, 116 which can be configured according to the invention, butthose of skill in the art will understand that suitable computernetworks include various networks, such as local area networks, widearea networks, metropolitan area networks, and/or various “Internet” orIP networks such as the World Wide Web, a private Internet, a secureInternet, a value-added network, a virtual private network, an extranet,or an intranet.

The system 100 shown as an example in FIG. 1 includes two local areanetworks 102, 104. Each network 102, 104 includes at least one computer106, and each computer 106 includes at least a processor and a memory;computers 106 also include various input devices and/or output devices.The processor may include a general purpose device such as a 80×86,Pentium (mark of Intel), 680×0, or other “off-the-shelf” microprocessor.The processor may include a special purpose processing device such as anASIC, PAL, PLA, PLD, or other customized or programmable device. Thememory may include static RAM, dynamic RAM, flash memory, ROM, CD-ROM,disk, tape, magnetic, optical, or another computer storage medium. Theinput device(s) may include a keyboard, mouse, touch screen, light pen,tablet, microphone, position sensor, pressure sensor, thermal sensor, orother input hardware with accompanying firmware and/or software. Theoutput device(s) may include a monitor or other display, printer, speechor text synthesizer, solenoid, switch, signal line, or other processcontroller.

The network 102, which is also by itself one of the many networkssuitable for use with the invention, includes a server 108 and severalclients 110. Other suitable networks may contain other combinations ofservers, clients, and/or peer-to-peer nodes, and a given computer mayfunction both as a client and as a server. For instance, network 104 isa peer-to-peer network. The computers 106 connected by a suitablenetwork may be work-stations, laptop computers 112, disconnectablemobile computers, servers, mainframes, clusters, network computers orlean clients, personal digital assistants or hand-held computing devices114, or a combination thereof.

A local network such as network 102 or network 104 may includecommunications or networking software such as the software availablefrom Novell, Microsoft, Artisoft, and other vendors. A larger networksuch as the network 100, may combine smaller network(s) and/or devicessuch as routers and bridges 116. Large or small, the networks mayoperate using TCP/IP, SPX, IPX, and other protocols over twisted pair,coaxial, or optical fiber cables, telephone lines, satellites, microwaverelays, modulated AC power lines, physical media transfer, and/or otherdata carrying transmission “wires” 118 known to those of skill in theart; for convenience “wires” includes infrared, radio frequency, andother wireless links or connections. Like the network 100, a suitablenetwork may encompass smaller networks. Alternatively, or in addition, asuitable network may be connectable to other networks through a gatewayor similar mechanism.

At least one of the computers 106 is capable of using a floppy drive,tape drive, optical drive, magneto-optical drive, or other means to reada storage medium 120. A suitable storage medium 120 includes a magnetic,optical, or other computer-readable storage device having a specificphysical configuration. Suitable storage devices include floppy disks,hard disks, tape, CD-ROMs, PROMs, random access memory, flash memory,and other computer system storage devices. The physical configurationrepresents data and instructions which cause the computer system tooperate in a specific and predefined manner as described herein. Thus,the medium 120 tangibly embodies a program, functions, and/orinstructions that are executable by computer(s) to protect and/or deleteemail message contents substantially as described herein.

Suitable software languages and tools to assist in implementing thevarious devices, signals, systems, and methods of the invention arereadily employed by those of skill in the pertinent art(s) using theteachings presented here and programming languages and tools such asJava, Pascal, C++, C, Perl, database languages, APIs, various systemlevel SDKs, assembly, firmware, microcode, and/or other languages andtools.

Personal Messaging with Self-Removing Messages

FIG. 2 illustrates a method and environment using self-removing messagesto carry messages from an originator 200 at some origin to one or a fewrecipients 202. As used here, “a few” means less than ten recipients, oralternatively, a small number of recipients who are personally known tothe originator; news items, notices, advertisements and/or othermessages directed to more than a few recipients are discussed elsewhereherein, although many of the tools and techniques taught herein applyregardless of whether there are only a few recipients.

During a creating step 204 the originator 200 creates a self-removingmessage 206 using software and hardware configured by the software, orusing custom hardware alone, according to the teachings herein. This maybe done generally in accordance with familiar tools and techniques foremail messaging, attaching files, embedding graphics, encrypting data,and/or compressing data, but it must associate code and/or hardware 208,and/or indicators 210, with the message 206 to perform or facilitate theself-removal message management functions described here. That is, theoriginator 200 (or equivalently, an embodiment under the originator'sdirection) marks the message 206 at the origin, includes removal code208 in the message 206, or does both. The code 208 may be embeddedsolely in the message 206, but it may also be embedded in plug-ins,modules, routines, objects, threads, or other forms in an ISP'stransmission program 224 and/or a recipient's browser or email receptionprogram 226, or the code 208 may be divided between one or more suchlocations. Code and/or hardware 208, and indicators 210, arecollectively termed “self-removal enhancements” herein.

In addition to the message self-removal code 208 in the message 206and/or elsewhere, the message 206 often includes one or moreself-removal indicators 210 such as bitflags, header values, file nameextensions, or other data marking the message 206, thereby identifyingthe entire message 206 or a portion thereof to the removal code 208 anddistinguishing the message 206 from messages which are not subject toremoval by the means taught herein. Of course, in a system where allmessages are entirely self-removing, the indicators 210 are optionalunless they are needed to detail information such as how long to displaythe message contents to the recipient, whether to allow recipients toscroll back through a previously displayed portion of the messagecontents, and so on. However, batch files, message handling rules, andother deletion controls that are provided by the recipient 202 are notindicators 210, since they do not give originators 200 and/ordistributors 222 the responsibility for, and the initial control over,removal of messages at the recipient's location.

In embodiments preferred for this present application, the originator200 or an embodiment under the originator's direction marks the message206 at the origin with one or more indicators 210 to facilitate theself-removal message management functions described here. In theseembodiments, removal code 208 is not included in the message 206.Instead, removal code 208 is embedded in plug-ins, modules, routines,objects, threads, or other forms in a recipient's browser or emailreception program 226. However, the initial decision to make a givenmessage be self-removing still rests with the originator 200 (or with anISP 222), rather than making the recipient 202 actively delete themessage.

In these presently preferred embodiments, self-removal indicators 210 ina given email message 206 permit the originator 200 and/or anintermediate node 220 to indicate to the removal code 208 one or more ofthe following options:

(a) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox shortly after being opened bythat recipient, e.g., delete the message approximately five minutesafter it is opened;

(b) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox no later than a specified timeafter being opened by that recipient, and may be deleted before thatspecified time, e.g., delete the message within 24 hours of receivingit;

(c) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox no sooner than a specified timeafter being opened by that recipient, and may be deleted any time afterthat specified time, e.g., give the recipient 24 hours to make copies,reply, forward the message or otherwise react to the message 206, butdelete it after that specified time has elapsed;

(d) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox no sooner than a first specifiedtime after being opened by that recipient, and no later than a secondspecified time after being opened, e.g., delete the message within oneto seven days of receiving it;

(e) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox no later than a specified timeafter being received, regardless of whether it has been opened by thatrecipient;

(f) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox no sooner than a specified timeafter being received, regardless of whether it has been opened by thatrecipient;

(g) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox between a first and secondspecified time after being received, regardless of whether it has beenopened by that recipient;

(h) the message 206 is to be deleted automatically by the removal code208 according to some combination of chronological and/or “has beenopened” criteria generally as discussed above, but the chronologicalcriterion is a fixed time or date, rather than an elapsed time, e.g.,delete the message 206 no later than Jul. 4, 2001 regardless of whetherit has been opened by that date;

(i) the message 206 is to be deleted automatically by the removal code208 according to some combination of chronological and/or “has beenopened” criteria generally as discussed above, but instead of deletingthe message only if it has been opened, or deleting it regardless ofwhether it has been opened, delete the message only if it has not beenopened, e.g., if the recipient doesn't bother to open the message 206because the subject line indicates it is an unwanted solicitation, thenthe message will be deleted automatically approximately one week afterit was received;

(j) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox, after it has been opened, whena specified storage limitation is reached, e.g., too many messages ortoo much storage used for messages;

(k) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox when a specified storagelimitation is reached, regardless of whether it has been opened by thatrecipient;

(l) the message 206 is to be deleted automatically by the removal code208 from each recipient's mailbox/inbox when the next message isreceived from the same source, regardless of whether the first messagefrom that source has been opened by that recipient, e.g., automaticallykeep for the recipient only the latest news item from a newslettersubscription;

Note that conventional options for handling attachments may be combinedwith the removal indicators 210. For instance, conventional emailclients such as the Eudora Pro 3.0 program permit one to specify whetheran attachment to a message should be deleted when the message ismanually deleted. In the present invention, a similar option can specifywhether to keep attachments when a self-removing message 206 isautomatically deleted.

Note that actions somewhat like these may be taken by a recipient,without any express removal indicator 210 in an email message. Forinstance, a recipient's email client 226 could be configured toautomatically delete any message which remains unopened for more thanone week. Likewise, a recipient's email client 226 could be configuredto make automatic deletion of a message be the default disposition afterthe message has been opened. That is, the recipient must manually savedesired messages, unlike the conventional approach in which recipientsmust manually delete undesired messages.

However, to clearly shift the burden of message removal from recipients202 to originators 200 and/or distributors 222, the message 206 includesone or more express removal indicators 210 which are placed there by theoriginators 200 and/or distributors 222 to make removal of the message202 an automatic default result. The actual deletion is performed by therecipient's software 226, but this is done in response to theinstructions 210 from the originator 200 and/or distributor 222. Thus, amessage subject line such as “GET RICH” or “HOT STOCK TIP” is not aremoval indicator 210, even if the recipient has installed a filter thatdeletes messages containing that subject line, unless the messageoriginator places the subject line in the message with the expectationthat the recipient's email tool 226 will automatically delete themessage in response to the subject line. Such subject lines areconventionally used to provoke an inquiry or another email reply, not toensure that the message will be automatically deleted by the recipient'ssoftware.

In short, a removal indicator 210 provides an originator 200 and/or adistributor 222 with initial control over the deletion of a messageafter the message reaches the recipient 202. The control is “initial” inthat, in some cases the recipient may override the instructions 210 ofthe originator 200 and/or distributor 222, such as by saving messagecontent 212 that would otherwise be automatically deleted. But thedefault handling of the message 206, i.e., the handling in the absenceof intervention by the recipient 202, is specified by the originator 200and/or a distributor 222 via the removal indicator(s) 210.

The message 206 normally includes content 212 which is meant to conveyinformation from the originator 200 to the recipient(s) 202. The messagecontent 212 may be in the form of text (e.g., word processor documents),images (e.g., still or motion image or video files), sounds (e.g., MP3,WAV, or other aural files), or other sensible items, and it may bein-line and/or provided as attachments. Word processors, conventionalemail tools, and other familiar tools and techniques may be used toselect and/or create the message content 212.

The message 206 optionally includes display code 214 and/or securitycode 216, each of which is discussed further below.

Unlike previous email systems, chat rooms, and other conventionalmessaging systems, the present invention thus gives email messageoriginators 200 and/or major service providers such as America Onlineboth the opportunity and the presumed burden of marking for removal atleast some of the messages 206 they originate or distribute. Inconventional email systems, by contrast, recipients are burdened withremoving essentially all unwanted messages. The invention promotesefficiency by having the originator 200 and/or distributor 222, who knowthe message contents 212 and their intended effect, mark the messages206 for removal after their arrival. This is better than making one ormany recipients, who did not necessarily ask to receive the message,attend to its disposal.

The invention also gives originators 200 and/or distributors 222 achoice regarding the transience of their message content 212 at therecipient's location. In conventional chat rooms and instant messagingsystems, by contrast, messages are ephemeral at the recipient's stationregardless of whether the originator or distributor wishes them topersist there, because they often scroll off the visible display windowor screen until they are beyond the recipient's reach.

During one or more transmitting steps 218 the message 206 is transmittedover the signal means 118 from the originator 200 to the recipient(s)202, possibly via a distributor 222. This may be done generally inaccordance with familiar tools and techniques for packet formation,storage, forwarding, error handling, and/or other network 100transmission means. As the message 206 travels over one or morenetworks, transmission software and/or hardware in bridges and/orrouters 116, servers 108 (including without limitation ISP servers andapplication servers), and other network intermediate nodes 220 haveaccess to part of all of the message. This access is facilitated byand/or subject to control by distributors 222, namely, ISPs (and otheraccess providers), other authorities, including governmentalauthorities, and other parties who are neither the message's originatornor the message's intended ultimate recipient. The nodes 220 operate atleast in part using conventional networking tools and techniques 224.After they have forwarded or otherwise processed in a conventionalmanner those portions, these novel intermediate nodes 220 can thendelete, shred, or otherwise enhance the security of the message 206portions by removing them as taught herein.

ISPs and other message distributors 222 may simply forward messages 206.However, the nodes 220 may also be enhanced according to the presentinvention. For instance, message removal software and/or hardware 208may configure the intermediate nodes 220 to provide novel capabilitieswhich include identifying packets or other message 206 portions, up toand including the entire message 206, through the self-removalindicators 210 and/or modifying messages 206.

For instance, distributors 222 may verify that email messages 206 from agiven originator 200 contain agreed-upon removal indicators 210. Inparticular, for the convenience of advertising message recipients, adistributor 222 may grant use of a member list of email addresses forlimited advertising purposes on condition that the emailedadvertisements contain indicators 210 which will cause them to beautomatically removed. The distributor 222 may then check some or all ofthe messages 206 to verify compliance with that contractual requirement.

Alternately, the agreed-upon removal indicators 210 may be actuallyinserted by the distributor 222, pursuant to a contractual requirementor to distributor 222 operating policy. Identification of messages forindicator 210 insertion may be based on the originator's email address,on the subject line of the message, and/or on other filtering criteria.For instance, an access provider 222 may insert removal indicators 210in all messages (regardless of origination address) which contain “$$$”in the subject line, so that those messages are automatically deletedone day after being opened or one week after being received, whicheveroccurs first.

For instance, an access provider 222 such as AOL, CompuServe, or Prodigymay permit controlled mailings to its members on condition that eachmessage 206 include an indicator 210 that will cause the message 206 tobe automatically removed from the recipient member's email “In Box”after the recipient member 202 opens it, unless the recipient 202actively overrides that removal to save the message's contents 212.Likewise, an ISP could use indicators 210 to implement a promise thatauthorized email advertisements will consume no more than onehalf-megabyte of a recipient's hard drive, by having the indicators 210set to cause automatic deletion of messages from a given list ofsources, thereby freeing drive space, when the total space used by allmessages from those sources exceeds a storage limit of onehalf-megabyte. Indicators 210 could likewise indicate that self-removingmessages 206 should be removed when the hard drive or partition holdingthem has only a specified amount of free space left, or when a specifiedpercentage of the total drive/partition space becomes used.

In some embodiments, the email tool 226 warns users that messages 206are subject to automatic deletion. Accordingly, a message 206 whichmeets the automatic removal criteria (e.g., “$$$” in the subject line)can be preserved by the recipient 202 if they so desire, despite theinsertion of removal indicators 210 by the access provider 222 and/or bythe message originator 200.

Eventually a transmission step 218 brings the message 206 to arecipient's station 226. This may be done generally in accordance withfamiliar tools and techniques, including without limitation web browsersand email programs adapted with at least removal code 208 according tothe invention through plug-ins or other means, and protocols such asSMTP, MIME, POP, IMAP, Privacy Enhanced Mail, listserv protocols, andusenet protocols. At the recipient's station 226 the message 206 isoptionally authenticated 228, optionally decrypted 230, displayed 232,removed 234 by removal code 208 operating in response to messageindicators 210 in the message 206, and optionally acknowledged 236. Eachof these steps is discussed at various points herein; at present, thefocus is on the displaying step 232 and the removing step 234.

During the displaying step 232, the message content 212 is displayed 232to the recipient 202. This may be done immediately upon arrival of themessage 206 without prompting from the recipient 202, or it may occur asa result of the message's icon or title being highlighted, opened,clicked on, or otherwise activated by the recipient 202. The displayingstep 232 may limit message contents 212 to volatile memory (as opposedto disk or other non-volatile storage), may prevent forwarding of themessage 206, may disable screen save functionality, may overwrite themessage contents 212 shortly after displaying them, may give therecipient 202 the option of overriding some or all of these defaultsettings, and so on, as described herein. In particular, the recipient202 may be warned that the message 206 is subject to automatic removal.

Finally, the message 206 is removed 234 by overwriting the window orscreen that displayed it, by deleting it or otherwise moving it from anIn Box to a Trash folder or the like, by marking the space it occupiesas free, by erasing its contents from disk, and/or in other ways, asdiscussed herein. Messages 206 may also be removed after being onlypartly displayed, or after sufficient time passes or some other eventoccurs, such as a reboot, or an browser restart.

Broadcasting with Self-Removing Messages

The novel tools and techniques illustrated in FIG. 2 can also be usedwhen the originator 200 sends a self-removing message 206 to more than afew recipients 202. For instance, public agencies and private litigantsmay wish to send messages 206 containing legal notices of the type whichare conventionally published in newspapers. In the case of publicagencies, email address databases could be compiled in connection withtax payments, corporate and professional license registrations andrenewals, driver license registrations and renewals, and similargovernmental functions. Care would be taken (and appropriate legislationand/or regulations put in place) to limit or prevent the use of suchgovernmental email address databases by private or quasi-privateentities.

However, private entities may appropriately use the invention, inaccordance with applicable law, to broadcast self-removing messages 206to large target audiences. For instance, a business might sendregistered customers new product announcements or press releases.Likewise, a private club or organization (or a business) might sendevent announcements to its members (or prospects) using self-removingmessages 206. Subscribers to newsletters or other news services may alsoreceive news items in the content 212 of self-removing messages 206.

Advertising and News with Self-Removing Messages

One email broadcast use of particular interest to businesses is the useof email for advertising. Another broadcast use is email news, in theform of newsletters, article summaries with links to articles on webpages, and the like. Such advertising and news broadcasts may be massmarket, or targeted demographic, or still more focused, as when a listof previous customer email addresses is used. However, conventionalemail advertising and news updates impose on the recipient at the sametime, sometimes doing so even as they directly or indirectly solicitbusiness from the recipient. Conventional approaches also consumestorage on intermediate network nodes, thereby imposing on InternetService Providers and similar entities (AOL, CompuServe, Prodigy, and soon).

By shifting the burden of message disposal away from recipients 202 andonto the system 100 and the originator 200, the invention reduces thetension created by simultaneously imposing on the recipient to disposeof the message and asking the recipient to investigate or purchase theadvertised products or services, or to visit the news provider's website, which often carries advertising. Reducing this tension will makedirect and indirect email advertising better received and hence moreeffective.

In one embodiment, self-removing email messages 206 containadvertisements of any of a broad range of services and goods which arepresently described in unsolicited mass-mailing emails, in websitebanner ads, in television or radio spots, in newspapers and magazines,and in other forms and media. In one embodiment, they contain news itemswhich are mailed to subscribers who voluntarily provided their emailaddresses for that purpose. Unlike television, radio, newspapers, andmagazines, ads and news sent through the Internet and other electronicmedia can be relatively inexpensive, targeted, interactive, and/orprovide hot links to web sites, newsgroups, IRC channels, and otherdigital network resources. Like unsolicited emails and banner ads, themessages 206 can be animated, with audio and/or visual components, andhot links. Unlike unsolicited emails and some banner ads, theself-removing message files 206 of the present invention do not requirethat recipients 202 affirmatively remove unwanted ads or old news fromtheir computer system disk or create a reply message having REMOVE inthe subject, to indicate their lack of interest in the subject matterbeing advertised, to conserve space, and/or to reduce clutter in theirinbox.

Self-removing email tools and techniques described herein can also beused to broadcast, multicast, or otherwise transmit explicit (intendedfor mature audiences only) materials without requiring permanent storageof such materials on the recipient's computer system. Some people 200,202 may find this useful for medical or health discussions, such assupport groups and professionals dealing with the difficult personal andsocial issues arising from conditions such as breast cancer or acquiredimmune deficiency syndrome. Some people may also find this useful forpersonal entertainment using sexually explicit materials. Within thebounds allowed by law, the invention may assist such uses.

Examples Focused on Recipient Convenience

FIG. 3 illustrates a subset of the embodiments illustrated in FIGS. 1and 2. Except as noted otherwise below, the illustrated steps andcomponents are as described elsewhere herein. However, these embodimentsfocus on increasing convenience to the recipient through automaticremoval of messages, rather than increasing security through suchremoval. Although security measures such as encryption, security code216, secure deletion in the form of electronic shredding, atomicity indisplay code 214, incremental overwrites while incrementally displayingmessage content, Print Screen disabling, message self-modification,searches for additional message copies, and authentication may beemployed in embodiments according to FIG. 3, they are not central to theinvention in such embodiments.

FIG. 3 also further illustrates the removal indicators 210, which may beused in embodiments according to any of the Figures. Four samplecategories of indicators 210 are shown. A first category of indicators300 includes indicators 210 which control automatic message 206 removalaccording to whether the message 206 has been opened by the recipient202. For instance, an indicator 300 may specify that the message 206 isto be deleted automatically by the removal code 208 from eachrecipient's mailbox/inbox within one to seven days of when the recipient202 opens the message 206 to read it.

A second category of indicators 302 includes indicators 210 whichcontrol automatic message 206 removal according to whether a fixed timeand/or date has been reached, or a specified time has elapsed since someevent such as original transmission of the message, receipt of themessage, or first opening of the message. For instance, an indicator 302may specify that the message 206 is to be deleted automatically by theremoval code 208 from each recipient's mailbox/inbox on Dec. 31, 2001.

A third category of indicators 304 includes indicators 210 which controlautomatic message 206 removal according to conditions involving areplacement message. A replacement message replaces a prior message, sothe prior message is deleted. For instance, an indicator 304 may specifythat the message 206 is to be deleted automatically by the removal code208 from a recipient's mailbox/inbox after that recipient receives thenext message from LawPlusPlus.com with “Update” in the subject.Similarly, an indicator 304 may specify that a message 206 is to bedeleted automatically by the removal code 208 from a recipient'smailbox/inbox if a replacement message is not received by the recipient202 by a specified date or within a specified period after the firstmessage 206 is received.

Earlier message(s) to be replaced may be identified in the replacementmessage by one or more values such as source address, date, or subjectline. Messages being replaced are preferably also identified by a key,certificate, password, or other authentication mechanism presented bythe replacement message to the removal code 208, in order to discouragemalicious “replacement” messages which are actually sent to deleteunrelated earlier messages.

A fourth category of indicators 306 includes indicators 210 whichcontrol automatic message 206 removal according to whether a storagelimit has been reached. For instance, an indicator 306 may specify thatthe message 206 is to be deleted automatically by the removal code 208from each recipient's mailbox/inbox after the number of saved messagesin a specified folder reaches one thousand, or after the amount of diskspace taken by the saved messages reaches three megabytes, or when thedisk partition has less than one megabyte of free space left.

A given indicator 210 may belong to more than one category. Forinstance, an indicator may specify that the message is to beautomatically removed when a replacement message arrives or one weekafter being opened, whichever occurs first.

More generally, FIG. 3 illustrates methods for using self-removingmessages 206 to make email messaging more convenient for messagerecipients by shifting the burden of message removal from the messagerecipient 202 to at least one of the message originator 200 and themessage distributor 222. Through removal indicators 210 and/or removalcode 208 which is associated with message content 212 by the messageoriginator 200 and/or the message distributor 222, the methods providethe message originator 200 and/or the message distributor 222 withinitial control over the deletion of a recipient copy of the messagecontent 212 after that content and the self-removal enhancement reachthe recipient 202. Unlike prior approaches, the message content copy atthe recipient's location may be automatically deleted in response tovarious criteria, even if the message containing the content 212 hasalready been opened by the recipient 202. As with other methods of theinvention, the methods illustrated by FIG. 3 may be embodied in softwarewhich configures a computer storage medium such as a CD, floppy disk,hard drive, ROM, or RAM.

The methods associate message content 212 with a self-removalenhancement such as one or more self-removing message indicators 210.The association between the message contents 212 and the self-removalenhancement is made by the message originator 200, by the messagedistributor 222, or both. It may be performed by placing removal code208 in the message (e.g., as an attachment). But it is preferablyperformed by placing one or more removal indicators 210 in the message(e.g., in an email header or an email subject line) with the content212.

In alternative embodiments, the method does not place the self-removalenhancement in the same message as the content 212 that is thus madesubject to removal. Instead, the method may associate message content212 with a self-removal enhancement by placing the enhancement in anemail message 206 which identifies a separate message, if the content212 is provided in the separate message. That is, the association may bemade by sending the email message contents 212 in one partialtransmission 218 to the recipient 202 and sending the self-removalenhancement in a separate partial transmission 218 (before or after thecontent 212 is sent), and by ensuring that the enhancement portion ofthe transmission 218 permits identification of the intended content 212.For instance, an ISP 222 may transmit to its member email tools 226 aninstruction which indicates that any subsequent message from an emailaddress specified in the instruction should be subject to automaticremoval one day after being opened, and that the recipient should bewarned of this when such a message is opened.

As with other methods of the invention, the methods illustrated in FIG.3 may be used with various types of content 212 in a variety of private,governmental, and/or commercial contexts. If the contents 212 includeadvertising, for instance, then the methods may obtain an email addressfor the recipient 202 from an email address database containing manyaddresses. Of course, the contents 212 may contain various types ofinformation, including advertisements, notices, news items, links to aweb site, and other content, including content identified elsewhereherein and/or content used in conventional messaging systems andmethods.

Inventive methods may be employed by the distributor 222, or by anauthorized agent/subcontractor/service/etc. acting for the distributor222, to verify that self-removing messages 206 are being used to shiftthe burden of message removal from message recipients 202. For instance,as indicated generally in FIGS. 2 and 3, in some systems the distributor222 receives at one or more intermediate nodes 220 a message intendedfor the recipient 202. The distributor 222 etc. may use software 208 tocheck the message to determine whether the message contains aself-removing message indicator 210. This may check for a particularindicator 210, or for more than one indicator 210, or for at least oneindicator 210 from a specified group of indicators 210. Checks forindicator(s) 210 may be performed by reading the email header, emailsubject line, and/or other expected location(s) of the indicator(s) 210.

The check for a self-removal enhancement in a given message may betriggered by one or more one predetermined check triggering criteriawhich indicate that a self-removing message indicator 210 should bepresent. A self-removing message indicator 210 itself is not atriggering criterion. In some cases, an indicator 210 or otherself-removal enhancement is expected because the message is from anentity that has an agreement with the distributor 222 permitting massmailings through the distributor 222 subject to use of the self-removalenhancement. For instance, the message may come from a source address ona list of advertisers who have mailing contracts with the distributor222 or a license to use the distributor's membership email database.

In other cases, a self-removal enhancement is not expected but shouldnonetheless be present because the message is part of an unauthorizedmass mailing. The check triggering criteria may include criteria fordetecting “spam” email through random sampling, conventional trafficmonitoring, suspicious address monitoring, and the like. For instance,the message may contain keywords or phrases that suggest it should besubject to automatic removal for the recipients' convenience. Themessage may have come from a source address that is sending a largenumber of messages in a short time, or from an address that isresponsible for numerous messages to nonfunctional destination addresses(“bounced” messages arising from use of an email database containingmany incorrect or obsolete addresses).

In short, check triggering criteria used by or for the distributor 222may identify the message as one that originates with an authorizedadvertiser or another authorized entity. In this case, the inventionallows the distributor 222 to monitor compliance with distributorcontracts and/or policies, laws, or regulations that require automaticmessage removal. Check determining triggering criteria may also identifythe message as one that originates as part of a mass mailing that wasnot expressly authorized. In that case, the invention provides thedistributor 222 with an option less extreme than the conventional choiceof either (i) allowing the mailing to continue as is, or (ii) attemptingto block it entirely. Instead, the messages that were not previouslyself-removing can be modified by or for the distributor 222 to add aself-removal enhancement, so that recipients 202 receive the messagesbut are not unduly inconvenienced by them. Conversely, the distributor222 etc. may strip out self-removal enhancements, so that messages 206are modified to become not self-removing.

If the checking step at the node 220 determines that the messagecontains or is otherwise subject to a self-removing message indicator210 as expected, then the node 220 transmits the message 206 on towardthe recipient 202. But if the checking step determines that the messagedoes not contain indicator(s) 210 as expected, then the message may beblocked to prevent further transmittal to the recipient 202, e.g., bybeing deleted, dropped, or rerouted back to the originator. Alternately,the lack of expected indicator(s) 210 may be remedied by inserting oneor more indicators 210 in the message and then transmitting theresulting message 206 from the intermediate node 220 toward therecipient 202.

At the recipient 202 (e.g., at the recipient's mail server and/or at therecipient's laptop, wireless device, or other workstation), removal code208 checks incoming messages to determine whether they contain anyself-removing message indicators 210 from message originators 200 and/ormessage distributors 222. The removal code 208 then automaticallynotifies the recipient 202, removes messages 206, and otherwise proceedsin response to such indicators 210 with each message 206 which containsor is otherwise associated with an indicator 210. Note that deletioninstructions provided by the recipient 202 are not indicators 210, sincethey do not give originators 200 and/or distributors 222 responsibilityfor, and initial control over, removal of messages at the recipient'slocation.

Additional Examples

Additional details regarding various embodiments of the presentinvention are provided below; “embodiment” refers to any system, method,signal, or configured medium according to the invention. Discussions ofa given embodiment also apply to other embodiments unless indicatedotherwise to one of skill in the art.

In one embodiment, a self-removing email file includes several messagecomponents 206 which display themselves in groups of one or morecomponents each, and then self-remove 234 the displayed 232 components.The display 232 of a given group may be triggered by an event such asarrival at the recipient's system 226, the opening of an outer emailenvelope, the launching of a certain application, the passage of apredetermined time period, or the arrival of a predetermined date.

In one embodiment, a self-removing email file's self-removal propertycan be expressly overridden by the sender 200, by the recipient 202, byan intervening authority 222 such as an ISP or an authorized governmentagency, or by some combination of these. In some cases, the override issilent, and in others the sender 200 or recipient 202 or both areautomatically notified of the override.

In some embodiments, a reply email (self-removing or not) is sent 236automatically to the sender 200 when the recipient 202 has opened theself-removing email message 206. In some cases, the possibility of areply is an explicit option presented to the user 200 or 202; in some ofthese cases, the options presented include one to send 236 a replyasking that the recipient 202 be removed from the mailing list. Thisallows the recipient 202 to request removal by doing little or nothingmore than opening the unsolicited message 206 and clicking on a “REMOVEFROM MAILING LIST” box or button. In some embodiments, the recipient 202is given the option of inserting text or other digital material in thereply.

In one embodiment, a message to be emailed is embedded in an executable(interpretable, etc.) file and the file 206 is emailed. When therecipient 202 tries to open the message 206 the executable portion runsan authentication operation 228. If the recipient 202 is authorized andthe message file 206 has not already been opened, then an executableportion 214 of the file 206 and/or a conventional part of the recipientstation 226 displays 232 the message. The message 206 then deletesitself, thereby deleting the displayed copy of the message andpreventing the code that did the display from redisplaying the messagelater. The deletion 234 may include an electronic shredding form ofdeletion, which overwrites the file (possibly several times) rather thanmerely marking it as free.

In one embodiment, the displaying portion 214 of the executable code andthe deleting portion 208 of the executable code are executed as oneatomic operation, with the atomicity enforced by the operating systemand/or by the particular processor on which the message file 206executes. Tools and techniques for enforcing atomicity are well known,in the database arts and elsewhere.

In one embodiment, the message file 206 incrementally overwrites itselfwhile incrementally displaying 232 its message, with the overwriting anddisplaying increments interleaved in their operation. After decrypting230 the message to form a block of message content 212 bytes in RAM,execution of displaying code 214 and removing code 208 is interleaved asfollows. The embodiment exchanges the video display bytes (which aresomething other than the message content 212) with the message contentbytes (which are placed in a format used by the video display buffer).Several bytes at a time may also be thus exchanged. Each exchangedisplays another increment of the message and also overwrites part ofthe message content 212 with whatever was previously being displayed.

In one embodiment, the message file 206 loads itself into memory,deletes itself from disk in partial or complete performance of an activeremoval step 234, verifies the deletion, and only then performs thedisplay operation 232. Concurrently with or shortly after the display,the message file may additionally overwrite itself in memory to completestep 234.

Tools and techniques familiar to those of skill in the art forself-modifying code and/or self-deleting programs such as self-deletingscripts or self-deleting installers may be helpful during implementationof particular embodiments of the invention. Likewise, techniques used inTrojan horses, worms, viruses, and other programs which hide and/orpropagate themselves may be modified for use in inventive email messagefiles 206 which destroy themselves after displaying the message theycarry. For instance, tools and techniques such as those employed in U.S.Pat. No. 5,623,600 may be adapted for use in the present invention.

In some embodiments, the message file 206 installs the message content212 (or the entire message file 206 itself) in locations on the harddisk and/or in memory which are subject to frequent overwriting oncedeallocated. Suitable locations include unused clusters temporarilymarked as allocated in file allocation tables, or swap files, orportions of RAM that are overwritten or scrambled during a reboot. Afterdisplaying its embedded message, the embodiment then marks itself (or atleast the portion containing the message) as deallocated and forcesoverwriting during step 234. For instance, the embodiment may force areboot to scramble or overwrite RAM containing the message or marktemporarily allocated clusters free once more.

The message content 212 may be encrypted so it cannot be read by simplyviewing the message file 206 in a debugger and looking for strings.During authentication 228, the message file 206 may also require apassword or key from the recipient 202 before decrypting 230 anddisplaying 232 the message.

Alternatively, the message file 206 may be self-decrypting (similar inspirit to self-extracting ZIP files) once it has verified its currentlocation 226 as the one corresponding to the intended recipient 202.Thus, copies on ISP servers or other intermediate network nodes remainencrypted, but the copy of the message file 206 at the recipient'snetwork address will decrypt 230 when launched.

Network addresses, environmental parameters such as the surroundingprocessor and operating system, previously sent ID files, digitalcertificates, tokens (software or hardware), and other means can be usedby the message file 206 to determine its present location. For instance,this can be done by checking the current IP or other network addressagainst an address specified (directly or in terms of an email address)by the sender 200. If the email connection is available, a packet canalso be sent to a specified location and the address on the responsepacket can be examined. Of course, the recipient's environment is notalways fully known, and it can be imitated. But imposing “properlocation” as a requirement for message content 212 display 232 makes itharder to gain unauthorized access to those contents 212.

In some embodiments, means are used to make the use of a debuggergenerally, and the use of break points or trace points in particular,result in self-destruction of the message file 206 without display ofthe message contents 212, or at least in a failure to decrypt anddisplay the message content 212. Suitable means 216 include (a) timedloops with conditionals that change behavior based on the time requiredto execute the loop (debugging is detected as unusually slow execution);(b) checksums on the current code 208 in memory (insertion ofbreakpoints alters the checksum); and (c) the interrupt vector table istemporarily modified to ignore keyboard and mouse input and hencedisable debugger commands (the message content 212 is displayed a presetperiod of time and then disappears forever).

In some embodiments, steps are taken by the security code 216 to disablethe Print Screen or similar command. For instance, a search forrecognized print screen routines can be made and they can be temporarilydisabled. Likewise, the interrupt vector table can be temporarilymodified to limit input and hence disable print screen commands.

In some embodiments, the message file 206 checks as much of the localenvironment as possible for other copies of itself and permanentlydeletes 234 them before displaying 232 the message content 212. Someembodiments only search for the message's file name in otherdirectories, while other embodiments search for files of the same lengthor recently created files and then examine those files more closely, incase the copy has been renamed. Techniques used to identify viruses canalso be modified to help the message file 206 identify copies of itself.

In some embodiments, techniques used in so-called “copy protectionschemes” are used by the security code 216 to help prevent copying ofthe message file 206. The techniques are modified to allow copying bynetwork system software as necessary for the message file 206 to travelacross the network 100 from the originator 200 to the authorizedrecipient(s) 202.

One embodiment does not initially delete itself after displaying themessage contents 212. Instead, the message file 206 removal code 208self-modifies to become a searcher. The searcher has a limited lifespan, measured either by elapsed time since its inception or by thenumber of times the searcher or its direct ancestors have been launchedfor execution.

Thus, the first time the message file 206 is run, it displays 232 themessage content 212, overwrites the message content 212, and notesinternally that it has done so. The next N-1 times it is launched, itruns as a searcher. The searcher displays a dummy message such as“Decrypting message; please wait . . . ” to gain time while actuallysearching for other copies and permanently deleting 234 them. Afterfinishing the search (and performing any appropriate deletions), thesearcher displays a message such as “Decryption failed. Please contact Xfor assistance.” X might be the message originator 200, the messagerecipient 202, or both, and/or their corresponding systemadministrators. The Nth time the searcher is run, the message file(searcher) permanently deletes 234 itself. In a variation, the searcher206 spawns additional searchers that behave in a similar manner.

In one embodiment, a timestamp representing a limited life span isembedded in the message file 206, and if the current time (as indicatedby a call made on the recipient's system) indicates that the intendedlife span has elapsed, then the message file simply deletes itselfwithout displaying the message contents. Tools and techniques such asthose employed in U.S. Pat. No. 5,786,817 may be adapted for use in thepresent invention.

Signals

Although particular methods and systems embodying the present inventionare expressly illustrated and described herein, it will be appreciatedthat apparatus, signal, and article embodiments may be formed accordingto methods and systems of the present invention. Unless otherwiseexpressly indicated, the description herein of methods of the presentinvention therefore extends to corresponding apparatus, signal, andarticles, and the description of apparatus, signals, and/or articles ofthe present invention extends likewise to corresponding methods.

For instance, the message 206 may embody novel signals such as theself-removal indicators 210, and/or the various codes such as removalcode 208 for performing the removing step 234, display code 214 forperforming the displaying step 232, and security code 216 for performingthe authenticating step 228 or other security-enhancing steps such asdisabling print screen or debugger functions. The signals may beembodied in “wires” 118, RAM, disk, or other storage media or datacarriers.

Articles of manufacture within the scope of the present inventioninclude a computer-readable storage medium in combination with thespecific physical configuration of a substrate of the computer-readablestorage medium. The substrate configuration represents data andinstructions which cause the computers to operate in a specific andpredefined manner as described herein. Suitable storage devices includefloppy disks, hard disks, tape, CD-ROMs, RAM, flash memory, and othermedia readable by one or more of the computers. Each such mediumtangibly embodies a program, functions, and/or instructions that areexecutable by the machines to perform self-removing message creation,transmission, removal, display or other method steps substantially asdescribed herein, including without limitation methods which performsome or all of the steps illustrated in FIG. 2. To the extent permittedby applicable law, programs which perform such methods are also withinthe scope of the invention.

Summary

In summary, the present invention provides a novel way to protectconfidential and proprietary email message contents withoutsubstantially reducing the ease and convenience of email transmission.In fact, the ease of use for email recipients is increased, because theyno longer need to imprecisely filter or manually remove unsolicitednotices or advertisements. Message originators also have more controlover the persistence of their messages after the messages are sent, evenif messages have been opened. ISPs and other distributors can verifyand/or insert self-removal instructions to make sure that directedmailings to their members comply with automatic removal requirements.

Increased security is achieved, for instance, when email messages areembedded in executable files, each of which displays its particularmessage once and then permanently deletes itself and any copies ofitself it can find. The message files may be embodied in computerstorage media or (while in transit) in network connections.

One embodiment employing message files at least for increased securityaccording to the invention includes the following:

uninstaller tools and techniques as a means for locating copies of themessage file;

copy protection tools and techniques as a means for preventing creationof copies of the message file except as needed by the message fileoriginator's email sending software, by the network transmissionsoftware, and by the intended recipient's email receiving software;

encryption tools and techniques as a means for encrypting the messagecontents in the message file and decrypting the message contents as partof an atomic display-and-self-destruct step;

virus detection tools and techniques, and uninstaller software tools andtechniques, each as a means for locating unauthorized or no longerneeded (e.g., copies made along the network transmission path after thereceived message has been displayed) copies of the message file (or ofan extracted message) to be permanently deleted;

electronic file shredder tools and techniques as a means for permanentlydeleting (erasing, removing, destroying) unauthorized or no longerneeded copies of the message file;

self-modifying code tools and techniques as a means for deleting themessage file as the message is being displayed and/or for modifying themessage file to spawn and manage searcher computer processes which seekout and permanently delete unauthorized or no longer needed copies ofthe message file;

anti-reverse engineering and obfuscation tools and techniques, anddigital signature or checksum tools and techniques, and interruptmanipulation tools and techniques, each as a means for protecting theintegrity and security of the message file contents prior to authorizeddisplay of the message, each possibly in conjunction with encryptiontools and techniques; and

email and networking tools and techniques as a means for authorizedcopying and transmission of the intact message file from the originatorto the intended and authorized recipient.

A particular order and grouping may be indicated in examples for methodsteps of the invention. However, those of skill will appreciate that thesteps illustrated and discussed in this document may be performed invarious orders, including concurrently, except in those cases in whichthe results of one step are required as input to another step. Forinstance, deletion from disk during step 234 may precede display of themessage during step 232, and may be filed by or interleaved withdeletion of message contents 212 from RAM. Likewise, steps may beomitted unless called for in the claims, regardless of whether they areexpressly described as optional in this Detailed Description. Forinstance, encryption steps, anti-debugger steps, and screen printdisabling steps are all optional actions by the security code 216, whichis itself an option component in the message 206. Steps may also berepeated (e.g., transmittal between nodes during step 218), or combined(e.g., atomic display and removal steps 232 plus 234), or nameddifferently.

The invention may be embodied in other specific forms without departingfrom its essential characteristics. The described embodiments are to beconsidered in all respects only as illustrative and not restrictive.Headings are for convenience only, and are not limiting. Trademarks usedherein are the property of their respective owners. Any explanationsprovided herein of the scientific, legal, or other principles employedin the present invention are illustrative only. The scope of theinvention is, therefore, indicated by the appended claims rather than bythe foregoing description. All changes which come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

What is claimed and desired to be secured by patent is:
 1. A method forusing self-removing email messages to shift the burden of messageremoval from a message recipient to at least one of a message originatorand a message distributor, the method comprising the steps of:associating message content with at least one self-removing messageindicator to provide at least one of a message originator and a messagedistributor with initial control over the deletion of a recipient copyof the message content after it reaches the recipient; and transmittingthe message content and the self-removing message indicator toward therecipient in at least one email message; wherein the self-removingmessage indicator indicates that the message is to be deletedautomatically in response to a condition involving a replacementmessage.
 2. The method of claim 1, wherein the self-removing messageindicator indicates that the message is to be deleted automatically if areplacement message is not received by the recipient by a specifieddate.
 3. The method of claim 2, embodied in software which configures acomputer storage medium.
 4. The method of claim 1, wherein theself-removing message indicator indicates that the first message is tobe deleted automatically if a replacement message is not received by therecipient within a specified period after the first message is received.5. The method of claim 4, embodied in software which configures acomputer storage medium.
 6. The method of claim 1, wherein theself-removing message indicator indicates that the message is to bedeleted automatically after a replacement message is received by therecipient.
 7. The method of claim 6, embodied in software whichconfigures a computer storage medium.
 8. The method of claim 1, whereinthe associating step associates message content with a self-removingmessage indicator by placing the indicator in an email message with thecontent.
 9. The method of claim 1, wherein the associating stepassociates message content with a self-removing message indicator byplacing the indicator in an email message which identifies a separatemessage and the content is provided in the separate message.
 10. Themethod of claim 1, wherein the associating step is performed by amessage originator.
 11. The method of claim 1, wherein the associatingstep is performed by a message distributor.
 12. The method of claim 1,wherein the method comprises obtaining an email address for therecipient from an email address database.
 13. The method of claim 1,wherein the method comprises transmitting message contents which includea notice.
 14. The method of claim 1, wherein the method comprisestransmitting message contents which include a news item.
 15. The methodof claim 1, wherein the method comprises transmitting message contentswhich include an advertisement.
 16. The method of claim 1, wherein themethod comprises transmitting message contents which include a link to aweb site.
 17. A method for removing email messages from a recipient'slocation in response to an instruction from a message originator, themethod comprising the steps of: checking an email message at therecipient's location to determine whether it contains a self-removingmessage indicator from the message originator indicating that themessage is to be deleted automatically in response to a conditioninvolving a replacement message; and automatically removing the emailmessage in response to the indicator if the message contains theindicator.
 18. The method of claim 17, embodied in software whichconfigures a computer storage medium.
 19. The method of claim 17,further comprising the step of a sending a reply from the recipient inresponse to the self-removing message.
 20. The method of claim 19,wherein the reply asks that the recipient be removed from a mailinglist.
 21. In a computer system, an improvement for using self-removingemail messages to shift the burden of message removal from a messagerecipient to at least one of a message originator and a messagedistributor, the improvement comprising at least one self-removalenhancement which is associated with message content by at least one ofa message originator and a message distributor, the self-removalenhancement specifying a condition for automatic removal of a copy ofthe message content from a recipient's location in response to acondition involving a replacement message.
 22. The system of claim 21,wherein the self-removal enhancement comprises a removal indicatorplaced in an email message.
 23. The system of claim 21, wherein theself-removal enhancement comprises removal code attached to the message.24. The system of claim 21, wherein the self-removal enhancement isassociated with the message by an ISP.
 25. The system of claim 21,wherein the self-removal enhancement includes an authenticationmechanism to permit authentication of a replacement message before areplaced message is removed.